1. The Field of the Invention
The present invention relates to systems and methods for manufacturing coaxial fiber optic components. More particularly, the present invention relates to systems and methods for manufacturing and packaging integrated coaxial fiber optic components for use in optical networks.
2. The Relevant Technology
Fiber optic networks are becoming increasingly common and have several advantages over existing electrical networks. One of the primary advantages of fiber optic networks is related to the bandwidth and data transmission potential of a fiber optic network. To effectively use, analyze, and monitor fiber optic networks, however, certain optical devices or components are often needed. One group of components or devices used in fiber optic networks is coaxial fiber optical components. Coaxial fiber optical components may be used to divide the light or extract a particular portion or frequency from the light being carried in the fiber optic network.
Fiber optical components include three-port optical components or devices, such as optical taps, add/drop modules, and the like. Fiber optical components are often used to extract a portion of the transmitted light beam or redirect a portion or particular wavelength(s) of the light beam. The light extracted or redirected by the optical component is often related to the purpose or function of the fiber optical component. For example, a fiber optic tap may be used to extract a small percentage of the entire light beam of an optical network. The extracted portion of light can be used to monitor the fiber optic network by using a network analyzer on the extracted portion.
Coaxial devices can also be used to extract information intended for a particular device on the network. In one example, a fiber-optic network may use a coarse wavelength division multiplexing (CWDM) scheme to increase the capacity of data transmittable in the fiber-optic network. A CWDM scheme transmits several channels of data along a single fiber-optic cable where the channels are defined by a carrier beam that is centered around a particular wavelength of light.
A three port optical component can be used to separate or combine a channel of interest from the other channels. In this case, all of the channels enter the optical component through one of the ports. The channel of interest is diverted such that it exits the three port optical component through one of the remaining ports. The remaining channels exit the three port optical component through the other port. Conversely, the three port optical component can also be used to add (combine) a channel back into the light stream.
Many of the problems associated with three port optical components and other devices such as optical taps, add/drop modules, optical isolators, and the like as well as other fiber optical components, relate to the manufacturing and packaging process of the particular optical component. Many of these optical components are assembled from discrete components. Problems related to optical alignment, optical matching, and transmission loss are often associated with optical components that are assembled from these discrete components.
FIGS. 1A, 1B, and 1C illustrate these and other problems that are often a result of a traditional manufacturing and/or packaging process. FIGS. 1A, 1B, and 1C illustrate the packaging process of a typical optical component. FIG. 1A illustrates a dual fiber sub-assembly 100 being attached with a filter substrate 104. The dual fiber sub-assembly 100 typically includes a dual fiber collimator 106 that is enclosed within a housing 102. The dual fiber collimator 106 typically includes a dual fiber pigtail and a collimating or focusing element such as a graded index (GRIN) lens.
The dual fiber sub-assembly 100 is a discrete element of many optical components. The optical alignment and optical matching of the finished optical component 130 (shown in FIG. 1C) is affected early in the manufacturing process when the dual fiber collimator 106 is pre made because the optical elements included in the dual fiber sub-assembly 100 may not be adequately aligned and/or matched. In addition, the transmission loss of the dual fiber collimator 106 may not be minimized.
The dual fiber sub-assembly 100 further includes a housing 102 that surrounds the dual fiber collimator 106. The housing 102 is necessary to ensure that the fiber pigtail and collimating or focusing element that make up the collimator lens 106 are securely connected. After the filter substrate 104 is attached with the dual fiber collimator 106, the dual fiber sub-assembly 100 is baked.
FIG. 1B illustrates the next steps in current manufacturing processes of many optical components including three port devices. The sub-assembly 100 is inserted into a housing 112 that is sufficiently large to accommodate the sub-assembly 100 and a single fiber collimator 120. The housing 112 includes holes 114 and 116 that are used to solder the housing 112 to the sub-assembly 100 and the single fiber collimator 120.
In this example, the three port device is manufactured by inserting the sub-assembly 100 into one end of the housing 112 and soldering the housing 112 to the housing 102 of the sub-assembly 100 using the holes 114. Similarly, the single fiber collimator 120 is also inserted into the opposite end of the housing 112 and soldered in place using the holes 116. Because both the sub-assembly 100 and the single fiber collimator 120 are mounted in the housing 112 in this manner, it is often difficult to ensure that they are adequately aligned and/or matched. In addition, the optical loss may not be minimized.
FIG. 1C illustrates a manufactured optical component. In addition to problems with optical alignment, optical matching, and transmission losses, the optical component 130 includes more than one housing. In particular, the dual fiber sub-assembly 100 includes a housing 102 that is independent of both the housing 112 and the housing 124 of the single fiber collimator 120. In other words, the housing 112 surrounds both the housing 102 of the sub-assembly 100 and the housing 124 of the single fiber collimator 120.
Generally, constructing a coaxial optical component such as the optical component illustrated in FIGS. 1A, 1B, and 1C requires that the discrete elements that make up the optical component 130 be separately purchased or pre-built and assembled. In this example, it is necessary to purchase or pre-build the dual fiber collimator 106, the filter substrate 104, the single fiber collimator 120, and the housing 112. The discrete elements are then assembled as described above. Because the individual elements are purchased or pre-built separately, the overall cost of the assembled optical component is increased due to reduced yield. Additionally, discrete elements that are purchased pre-built and assembled in this manner may not be adequately matched and/or aligned. Further, some of the discrete elements are redundant.